You do know the Ps3 version of Oblivion had better graphics than the 360 version and that usualy the case for most games and i have both so i m not being a really devoted fan or anything just saying
That's usually not the case, actually. All of the games that I have for 360 look the same as their PS3 equivalents except for Oblivion, which I blame on Bethesda not taking advantage of the optimization that they had an extra year to do on the PS3. Hardware teardowns that I've seen are conflicting, where the PS3 is better, the Xbox is better, they are both the same, or they both have certain parts that are better than the other. Who's to know for sure. I am of the opinion that developers usually don't bother making two versions of the same game, just to take advantage of barely better graphics of whatever system. The biggest edge that the PS3 has over the 360 is BluRay, not performance. Considering Skyrim will be using a single disc on the 360 anyways, it doesn't make a difference.
That being said, I will suggest Xbox. In general I find the experience to be better than the PS3, and given Sony's latest catastrophe, my trust in that company is at an all-time low.